Inhibition Behavior and Surface Analysis of Inhibitors for Copper in Seawater

The inhibition behavior of inhibitors for copper in seawater had been investigated by weight-loss,electrochemical polarization,SEM and XPS.The results indicated that there was a synergistic effect between benzotriazole and sodium citrate.When benzotriazole was 2 mg/L and sodium citrate was 20 mg/L,corrosion inhibitor for copper had an inhibition efficiency of 96.0%,and corrosion rate was 0.01 mm/a.The polarization curves in seawater indicated that the compound inhibitor of BTA and sodium citrate was a mixture inhibitor.The results of SEM and XPS indicated that the inhibitor formed a water-fast protective film of Cu2O,Cu(Ⅰ)- BTA and Cu(Ⅰ)-complex on copper surface.The film could restrain the Cu dissolving as Cu+ and Cu2+ in seawater.